Wireless sensor devices are used in a variety of applications including the posture detection and activity monitoring of users. In many of these applications, a wireless sensor device is attached directly to the user's skin (e.g. near the chest area) to measure certain data. This measured data is then utilized for the posture detection and activity monitoring of the users.
Detecting posture from a patch form-factor chest-mounted wireless sensor device (e.g. accelerometer) is difficult if proper calibration is not performed. This is due to the fact that the patch can be worn in different positions making it difficult to distinguish postures if only non-calibrated accelerometer data is available. Therefore, there is a strong need for a cost-effective solution that overcomes the aforementioned issues. The present invention addresses such a need.